1. Field of the Invention:
The present invention relates to a slider for a slide fastener.
2. Prior Art:
Japanese Patent Publication (Kokoku) No. 48-35425, issued Oct. 27, 1973, discloses a method of correcting a longitudinal divergence or deviation in interengagement between a pair of fastener stringers of a slide fastener, each stringer having a row of fastener elements in the form of resilient synthetic resin filament sewn to a tape along its inner longitudinal edge. In the method, one fastener stringer is threaded through a slider, and then the other fastener stringer is introduced into the slider. The slider is then moved forwardly to some extent along the opposed fastener element rows of the fastener stringers to interengage the same, thus providing a longitudinal divergence or deviation of interengagement between the fastener stringers. After that, the fastener stringers are pulled on their bottom ends laterally in opposite directions until such bottom end portions are disengaged all the way to the rear end of the slider. Thereafter, with the slider and one fastener stringer are held stationary, the other fastener stringer is forcibly moved lengthwise against the resilience of the fastener elements until the bottom ends of the opposed stringers are aligned with one another. Finally, the slider is forcibly moved backwardly almost all the way to the bottom ends of the stringers against the resilience of the fastener elements, and is then moved forwardly.
Known sliders for use in such divergence correction generally comprise a slider body including a pair of upper and lower wings each having a flat interior surface. However, with such prior slider, the stringers having the fastener elements are pressed against the flat interior surfaces of the slider body with great frictional resistance when one or both fastener stringers are forcibly moved through the slider against the resilience of the fastener elements, during which time the individual fastener elements are deformed. This great frictional resistance not only causes nonsmooth movement of the stringers through the slider, but also causes fastener-element-holding threads to be easily broken or otherwise damaged.